PHILADELPHIA (KYW Newsradio) — Bryce Harper jerseys have been wildly popular, ever since the Philadelphia Phillies signed him last month. Now, the feds say overseas counterfeiters are trying to steal a piece of the action.

Over the last few weeks, the U.S. Customs and Border Protection says they have been intercepting counterfeit Harper jerseys at air parcel locations in Philadelphia.

"Since opening day, Customs and Border Protection has seized 314 Harper jerseys,” said CBP spokesman Steve Sapp. “It comes out to about $44,000 if they were actually authentic."

"Bryce Harper jerseys, the counterfeit jerseys, were coming in from China and they were being delivered to multiple addresses in Pennsylvania, New Jersey and Delaware,” he said. “Obviously if it's a onesie and twosie in a package, you're looking at probably private use. However, the majority of our seizures are anywhere from 18 to 15, with as many as 204 -- which leads us to believe they were being resold."

Sapp says not only are counterfeit jerseys made with substandard materials, but they violate the trademark rights of Major League Baseball and the Phillies.

He goes on to say that this fake merchandise is sold on dozens of websites, but says as quickly as authorities close those sites the counterfeiters create new ones.